Along with the rapid development of Internet applications and intelligent terminals, the user needs of accessing to the Internet through a variety of intelligent terminals such as smart phones, tablet computers, and so on, so as to work, communicate and entertain anytime and anywhere are also very popular, the user accessing a network via the wireless local access network (WLAN) is one of the most important means.
FIG. 1 is a schematic diagram of the topology of a WLAN in the related art. As shown in FIG. 1, a conventional WLAN comprises access points (AP), access controllers (AC), an authentication and authorization and accounting (AAA) server, and other network elements, the user terminal device can access the network via the AP and AC after passing the authentication by the AAA server, the AC manages and controls the AP device via the control and provisioning of wireless access points (CAPWAP) protocol. With the trend and development of network integration, the integration of the WLAN network and the fixed broadband network has become one of the main trends of the future. FIG. 2 and FIG. 3 are schematic diagrams of network topology in a mode of integrating the WLAN and the fixed broadband network in the related art. As shown in FIG. 2 and FIG. 3, the various types of user terminals access the fixed broadband network via the WLAN network and the wired link, and the user authentication and service control are systematically executed by the broadband network gateway (BNG), while the AC device in the WLAN network is only responsible for the management and service configuration of the AP device, one AC device or a “AC cloud” manages a plurality of AP devices which are respectively linked to the upper-layer network through different BNGs. Meanwhile, because of the large area penetration and rapid deployment of the WLAN hotspot area networks, the needs for the mobile terminals accessing the network services via the WLAN in mobile scenarios are also increasing, the WLAN hotspot area networks need to support the user-based roaming and mobility capability. In the current broadband access network, however, in order to prevent problems such as account theft and remote login, the identification information (account number, password) of the fixed broadband user is bound with the user location information during the authentication, and the user location information is added by the access network device (such as OLT, DSLAM, Ethernet switch, and so on), the terminal cannot fake. Regardless of whether binding the user location information to authenticate or not, when a fixed broadband user successfully passes authentication and accesses, the user's access location information is also confirmed, the user cannot constantly access the network in the case that the location moves, or the access location information changes. This results in that, in a network environment where the fixed broadband users and the WLAN users coexist, the existing BNG device cannot effectively distinguish these two types of users and is unable to provide the mobility access capability for the WLAN users.